A056013 Numbers n such that n | sigma(n) - d(n) + phi(n).

1, 2, 27, 65120, 3332064, 21940224, 351952896, 123346213728

Offset

1,2

Links

Table of n, a(n) for n=1..8.

Maple

with(numtheory): A056013:=n->`if`(sigma(n)-tau(n)+phi(n) mod n = 0, n, NULL): seq(A056013(n), n=1..10^5); # Wesley Ivan Hurt, Apr 26 2017

Mathematica

Do[If[Mod[DivisorSigma[1, n]-DivisorSigma[0, n]+EulerPhi[n], n]==0, Print[n]], {n, 1, 10^7}]

Crossrefs

Cf. A000005, A000010, A000203.

Sequence in context: A076113 A182335 A362288 * A363403 A007257 A045487

Adjacent sequences: A056010 A056011 A056012 * A056014 A056015 A056016

Keyword

nonn

Author

Robert G. Wilson v, Jul 24 2000

Extensions

a(6)-a(8) from Donovan Johnson, Nov 12 2012

Status

approved